1. Field of the Invention
The invention concerns a method and arrangement for manufacturing a wire or cord for welding floor covering, such as linoleum, or an artificial fibre floor covering, with colours and patterns, which filler wire forms a firm joint with the edges of the floor covering, which are placed beside one another, under the influence of a thermal process, all this in such a way that there is hardly any difference in colours and patterns between weld and floor covering.
2. Description of the Related Art
From the German patents specification 4339169 a filler wire is known, with which after welding the joint between the floor covering the distinction between the weld and multi-coloured floor covering had also entirely or almost entirely disappeared, so that the impression of an uninterrupted floor covering arises. However, the manufacturing of this filler wire takes place by multiple application of heat and pressure on the previously formed strips for the welding material, which renders this known method labour-intensive and inefficient.
The invention now introduces a method and arrangement with which the filler wire or cord can be obtained in a simple, efficient and reliable manner. To this aim, according to the invention, the method is characterised in that a mixture is made of coloured granules whether or not of a random grain form, which is transported to a heating system, where the mixture is subjected to a heat treatment in such a way that a molten and coloured mixture with a pattern arises, which is then further transported to a cooling system in which the mixture is cooled down into a sheet, which can be cut into filler wires or strips by a cutting machine.
Preferable is the method according to the invention, which is characterised in that the mixture is mainly formed by granules based on polymers to which suitable resins, kinds of wax and/or weakeners are added, where the polymers may consist of polyvinyl acetate, polyamide, polyethylene, polypropylene and polyvinyl chloride. Thanks to the size, form and distribution of the colours in the mixture, the desired filler wires can finally be cut from the fixed sheet.
There is an advantage in the application of the method in which the diameter or thickness of the granules is approximately between 0.1-10 mm and the granules have entirely random shapes, e.g. round, bar-shaped, polygonal oval, etc.
Another favourable circumstance is that heating of the mixture takes place between 50xc2x0 and 350xc2x0 C. Preferable here is the method that is characterised in that the mixture is transported to a heat resistant conveyor belt and is transported through the systems this way.
Optimal results are obtained when, according to the invention, on the conveyor belt the mixture is subjected to temperatures between approximately 50xc2x0 and 220xc2x0 C. at the top and between approximately 50xc2x0 and 350xc2x0 C. at the bottom.
A favourable result is obtained according to a method which is characterised in that the molten mixture is cooled down on the conveyor belt during a course of approximately 50xc2x0-0xc2x0 C. In this manner an (inflexible) sheet, which reflects the desired colours and patterns, is obtained.
The arrangement for obtaining a filler wire or cord by the method according to the invention is mainly characterised by an endless, movable, heat resistant conveyor belt, at the end of which there is a funnel to catch, guide or mix the granules, where below the funnel a duct is used, which connects to the conveyor belt and beyond the transition from duct to conveyor belt means have been applied with which the granules that are transported on the belt can be spread over the width of the belt in an even thickness and near the means a heating system as well as, at some distance, a cooling system have been applied, along which the conveyor belt can be moved.
Preferable is the application of the arrangement according to the invention, which is characterised in that the means for evenly spreading the granules on the conveyor belt are mainly formed by an adjustable levelling element that is placed over the width of the belt, the bottom of which can level the mixture of granules in order to form an even top layer and layer thickness. It is also advantageous if connected to the funnel a vibrating duct is applied, so that an effective mixing can be achieved.
Advantageous is an application according to the invention which is characterised in that a conveyor belt, at least in its longitudinal direction, is provided with grooves the cross sections of which are mainly angular, trapezoidal, round U-shaped. By this measure a filler wire is efficiently obtained, which exactly fits in the joints between floor coverings placed next to each other, the sides or edges of which have straight, slanting, circular or bowed cross sections, respectively.
In a preferable application the heating system that is applied at some distance from the levelling means, is provided with adjustable heating elements, with which the top and/or bottom of the mixture that is present on the conveyor belt may be heated as desired, so that the desired stadium of molten granules is determined this way.
Preferable is the application which is characterised in that a cooling system is applied at some distance from the heating system, with which the molten mixture from the heating system can be cooled or moulded, respectively, into a fixed sheet.
Efficient is an application of the arrangement to which a cutting machine is connected, with which the multi-coloured and patterned sheet transported by the conveyor belt can directly be cut into cords of different lengths and cross-sections. This cutting machine can be equipped with a rotating knife or knives that swing to and fro, depending on the sheet material that is finally formed.
By the previously described measures the mixture of filler wire granules is effectively and reliably molten into a multi-coloured mixture, partly or completely as desired, and then cooled down into a fixed sheet, the colour and pattern of which practically correspond with that of the floor covering that must be welded. As mentioned before, a filler wire or cord can be cut from the sheet with a cutting machine. With a welding arrangement the filler wire can then be welded into the joint between floor coverings, in such a way that the joint is fully closed, so that on the one hand liquids, cleaning agent, etc, can not penetrate between the joint edge and the edge of the floor covering, on the other hand the effect of a fully similar floor covering that is laid without any interruptions arises.
For the sake of clarity we must also state that the filler wire is suitable for artificial fibre floor covering or floor covering that is mainly manufactured of natural raw materials, depending on the composition of the mixture.